Information on this page is from History of Rensselaer Co., New York by Nathaniel Bartlett Sylvester, published in 1880.

JOHN FLAGG was born in the town of Weston, Mass., April 25, 1799. He is a lineal descendant, of the eighth generation, from John Flagg, who was born in Norfolk Co., England, 1616, who came from England in 1637 in the service of Richard Scratby, and settled at Watertown, Mass. His father, John Flagg, was also a native of Weston; married Lucy Curtis; lived in the place of his birth his whole life, and for many years was a merchant. He died at the age of fifty-four. His wife died in 1830.

Mr. Flagg received a good education before reaching his majority, and at the age of nineteen had prepared for college. Concluding to lead a business instead of a professional life, in 1818 he spent one year as clerk in a store in Boston, followed by four years as book-keeper in a commission house in New Orleans. He then went to Nashua,
N. H., and established mercantile operations which he continued for fifteen years. He became subsequently a merchant in New York City for six years, where by trying to assist his friends he unfortunately lost his entire property.

With that undaunted resolution, which was so characteristic of his early life, to meet every obstacle with a determination to succeed, he again began at the bottom of business, with no capital, but something of more value,— experience. He came to Troy in 1848, when he opened a dry-goods house, and by his close attention to business, and his integrity in all his relations with his fellow-men, he was soon in the midst of a prosperous trade, which he carried on successfully until 1874. For many years he was a leading merchant of the city, and for a part of the time was interested in three different houses in the city at the same time. He has been connected with the following firms Flagg, W Winne & Co.. Flagg, King & Blakeman, and Flagg & Frear. Few men remain for so many years in one business, and few men retain the vigor of body and mind that Mr. Flagg seems now to possess after a business career of sixty years, fifty-five of which have been spent as a merchant.. His life has been one of constant activity, giving little attention to the bickerings and strife of politics, except to cast his vote. He was formerly identified with the Whig party, and is now a Republican.

Mr. Flagg is modest and unpretentious, yet sociable and genial, and is known to the citizens of Troy as a man of sterling qualities; upright, honorable, and possessed of great kindness of heart for the welfare of all with whom he comes in contact; and especially is his sympathy manifested to those worthy and in need. Morally, he has ever been an example worthy of imitation by the rising generation. A friend to the friendless, in his business relations he has in many instances been the means of encouraging, assisting, and directing young men to successful positions in business life.

Mr. Flagg has always manifested a warm interest in educational and religious institutions, and has been a liberal contributor to them whenever duty made it incumbent upon him.

In 1830 he married Abigail, daughter of Isaac Hobbs, of Weston, Mass. She was a lady of rare excellence, and died in 1870, aged sixty-nine. Mr. Flagg is now in his eighty-first year, and has buried eight brothers and sisters, his wife, and three children, leaving only a grandson of his posterity; and, although he has lived to exceed fourscore years, his mind seems unimpaired, and his activity and sprightliness of body, when out for his accustomed drive or walk, bespeak a man not rising of fifty years.